Cadence PCIe host and endpoint controllers
Linux support for the Cadence PCIe controller IP that SoC vendors license and embed in their chips, covering both root-complex (host) and endpoint modes. It powers the PCIe slots and M.2 connectors on platforms like Texas Instruments' J721E/AM69A automotive and edge-AI processors and the Sophgo SG2042 RISC-V server chip used in the Milk-V Pioneer workstation board.
recommendation
It should stay because this is the active upstream home for Cadence-based PCIe controllers shipping in current silicon. Maintenance is ongoing — TI's J721E glue code was still getting fixes in 2026, and a substantial new Cadence HPA support series landed in late 2025 — and there are real products on sale today (TI AM69A, Milk-V Pioneer/SG2042) that depend on it.
repository signals
sources
- lore.kernel.org
`pci-j721e.c` was still receiving upstream functional fixes in March 2026 ('PCI: j721e: Validate max-link-speed from DT'), indicating active maintenance rather than retirement.
- lore.kernel.org
`pcie-cadence-hpa.c` was added through an 11-version 2025 patch series for Cadence HPA support, showing ongoing feature growth in this directory.
- ti.com
TI listed AM69A as ACTIVE and specifies up to four PCIe Gen3 controllers, supporting that Cadence-based TI J721E/AM69-class deployments are current, not legacy-only.
- milkv.io
Milk-V documents the current SOPHON SG2042 processor with integrated PCIe controllers, confirming present-day hardware using this driver family.
- milkv.io
Milk-V markets the Pioneer board as a purchasable SG2042 platform with PCIe slots/M.2, showing live deployment hardware rather than purely archival silicon.
codex reasoning notes (technical)
Real driver directory: Kconfig/help and source names show Cadence-based PCIe host/endpoint controllers for multiple SoC vendors. lore_file_timeline on the directory returned no hits, so I fell back to lore_activity on representative files. `lore_activity(file=drivers/pci/controller/cadence/pci-j721e.c)` produced March 2026 maintenance patches; `lore_activity(file=drivers/pci/controller/cadence/pcie-cadence-hpa.c)` produced a large 2025 feature series adding HPA support. That is strong evidence against deprecation or removal. Deployment evidence came from web search results on official/current product pages: TI AM69A (ACTIVE, PCIe Gen3 controllers) and Milk-V SG2042/Pioneer pages. No natural upstream replacement exists; this directory is the current Linux support stack for Cadence PCIe IP embedded across several modern SoCs.